NOMA for Future Cellular Systems

Recently, non-orthogonal multiple access (NOMA) has gained more attention as a candidate multiple access scheme for future radio access. A major reason for this is that NOMA has the potential to achieve a more favorable tradeoff between system efficiency and user fairness than orthogonal multiple access (OMA), which is adopted in the 4th generation mobile communication systems such as LTE and LTE-Advanced. In this paper, we focus on downlink cellular systems. This paper gives an overview on the principle of NOMA and recent investigations. Several issues for implementing NOMA in real systems are also presented.